There have conventionally been an audio coding apparatus and an audio decoding apparatus, which access a portion that is not music information to output music (e.g., refer to Japanese Published Patent Application No. 2006-114148).
FIG. 9 shows a format on a CD for recording an audio signal. FIG. 10 is a flowchart for explaining the operation of the conventional audio decoding apparatus.
Hereinafter, the operation of the conventional audio decoding apparatus will be described along the flowchart shown in FIG. 10 with reference to FIG. 9.
The conventional audio decoding apparatus reads data in a read IN area (900 in FIG. 9), and reads TOC information of the disk (step ST1).
Then, the audio decoding apparatus extracts control codes of the respective tracks from the read TOC information (step ST2), and judges whether the CD is a CD-DA audio disk or a CD-ROM disk (step ST3).
When the CD is a CD-DA audio disk, the audio decoding apparatus performs CD audio playback based on the TOC information (step ST12), and thereby performs music playback as an ordinary CD player.
On the other hand, when the CD is judged as a CD-ROM disk, the audio decoding apparatus reads the contents of a CD-ROM pass table (901 in FIG. 9), and thereby reads a file structure as a CD-ROM (step ST4).
The audio decoding apparatus confirms the read file structure, and judges whether a compressed audio file is present or not from such as a file extension (step ST5), and terminates the processing when no compressed audio file is present. Subsequently, the audio decoding apparatus confirms whether an information file (903 in FIG. 9) is present or not from such as the file extension (step ST6).
When no information file is present, the audio decoding apparatus performs extraction of the compressed audio file on the basis of the contents of the CD-ROM file system with reference to the pass table (901 in FIG. 9) (step ST10), and starts up a compressed audio playback program (step ST11) to perform playback of the compressed audio.
On the other hand, when an information file is present, the audio decoding apparatus reads the contents thereof (step ST7), and forms a music playback list (step ST8).
In addition, the audio decoding apparatus extracts the respective file names and playback start addresses (absolute addresses) from the playback list (step ST9).
The conventional audio coding apparatus performs coding based on the format shown in FIG. 9 so that the coded data are reproduced by the above-described audio decoding apparatus.
In the conventional audio coding apparatus, a music playback list is formed using the data other than the compressed audio data to give associations between titles and audio data, while in the audio decoding apparatus, coded audio data is decoded using these associations to reproduce audio.
However, since in such associations between titles and audio data in the audio coding apparatus, link with the compressed audio data is performed by only information such as playback start address, it was not possible to process the compressed audio data itself thereby to output various kinds of audio data.